Abstract: Provided are a high-strength cold rolled steel sheet that has a tensile strength of 980 MPa or more, excellent ductility, and a low failure rate in a hole expanding test, and a method for manufacturing the same. A high-strength cold rolled steel sheet comprises a predetermined composition, wherein a total area ratio of ferrite and bainitic ferrite is 20% to 80%, an area ratio of retained austenite (RA) is more than 10% and 40% or less, an area ratio of tempered martensite is more than 0% and 50% or less, a ratio of RA with an aspect ratio of 0.5 or less is 75% or more, a ratio of RA with an aspect ratio of 0.5 or less in ferrite grain boundaries is 50% or more, and an average KAM value of bcc phase is 1° or less.

Abstract: A steel material for a low yield ratio, high-strength steel pipe having excellent low-temperature toughness according to an aspect of the present invention comprises, by weight %, 0.03-0.065% of C, 0.05-0.3% of Si, 1.7-2.2% of Mn, 0.01-0.04% of Al, 0.005-0.025% of Ti, 0.008% or less of N, 0.08-0.12% of Nb, 0.02% or less of P, 0.002% or less of S, 0.05-0.3% of Cr, 0.4-0.9% of Ni, 0.3-0.5% of Mo, 0.05-0.3% of Cu, 0.0005-0.006% of Ca, 0.001-0.04% of V, and the balance of Fe and inevitable impurities, wherein a number of deposits having an average diameter of 20 nm or less per unit area in a cross section of the steel material may be 6.5*109/mm2 or greater.

Abstract: The present invention provides a steel material which is excellent in both of the strength (particularly, fatigue strength) and the manufacturability (particularly, bending straightening properties), and thus can be used as an automobile component such as a crankshaft by being formed into a product shape, being subjected to a high strength treatment such as a nitrocarburizing treatment, and then being subjected to the bending straightening.

Abstract: A low alloy, high performance steel having high impact toughness and high ductility, as well as methods of making and heat treating the alloy, are provided. The alloy steel composition consists essentially of about 0.24% to about 0.32% carbon, about 2.00% to about 3.00% chromium, about 0.50% to about 1.50% molybdenum, about 0.05% to about 0.35% vanadium, about 1.00% manganese or less, about 3.00% nickel or less, about 1.50% silicon or less, with minimal impurities, and balance consisting essentially of iron, wherein % is weight percent based on the entire weight of the alloy steel composition. The impurities may include about 0.20% copper or less, about 0.015% phosphorous or less, about 0.012% sulfur or less, about 0.02% calcium or less, about 0.15% nitrogen or less, and/or about 0.025% aluminum or less. Also disclosed is a hardened and tempered article that has high impact toughness, as well as other favorable physical properties.

Abstract: According to exemplary practice of the present invention, a steel composition includes, by weight, 0.07 to 0.15% C, 9 to 11% Ni, 0.8 to 1.2% Mo, 0.05 to 0.10% V, and further includes additives and/or impurities, with the balance being Fe. An iron alloy having such composition is produced and then undergoes heat treatment that includes quenching, lamellarization according to a 30 minute holding duration and a temperature span of 625° C. to 665° C., and tempering according to a 60 minute holding duration and a temperature span of 575° C. to 605° C. Exemplary embodiments of the inventive steel afford superior material properties including yield strength of at least 129 ksi, tensile strength of at least 157 ksi, elongation of at least 23%, and Charpy impact energy of at least 112 foot-pounds at ?120° F.

Abstract: A stick electrode for depositing an high strength weld metal bead on a workpiece where the yield strength of the weld metal is between 85 ksi and 125 ksi irrespective of the cooling rate. The electrode deposits weld metal having 0.80-1.85% by weight manganese, 0.25-0.50% by weight molybdenum, 1.25-2.50% by weight nickel, and less than 0.07% by weight carbon, wherein the ratios of the carbon, manganese and molybdenum are adjusted to provide a carbon equivalent in deposited weld metal in the range of 0.17 to 0.30 and preferably less than 0.22.

Abstract: A steel for wheel contains, in mass %, C: 0.65 to 0.84%, Si: 0.4 to 1.0%, Mn: 0.50 to 1.40%, Cr: 0.02 to 0.13%, S: 0.04% or less and V: 0.02 to 0.12%, wherein Fn1 expressed by formula (1) is 32 to 43, and Fn2 expressed by formula (2) is 25 or less, the balance being Fe and impurities. P, Cu and Ni as impurities are P: 0.05% or less, Cu: 0.20% or less and Ni: 0.20% or less: Fn1=2.7+29.5·C+2.9·Si+6.9·Mn+10.8·Cr+30.3·Mo+44.3·V??(1) Fn2=exp(0.76)·exp(0.05·exp(1.35·Si)·exp(0.38·Mn)·exp(0.77·Cr)·exp(3.0·Mo)·exp(4.6·V)??(2). The steel has excellent properties for use as a wheel.

Abstract: Provided is a mold steel for plastic injection that is excellent in fatigue strength and tensile strength and available for long term use, where the mold steel includes: 0.15 to 0.40 wt. % of carbon (C), 0.15 to 0.50 wt. % of silicon (Si), 0.70 to 1.50 wt. % of manganese (Mn), 0.50 to 1.20 wt. % of nickel (Ni), 1.50 to 2.50 wt. % of chrome (Cr), 0.25 to 0.70 wt. % of molybdenum (Mo), 0.20 wt. % or less of vanadium (V), 0.010 wt. % or less of boron (B), and a trace of iron (Fe) and a plurality of impurities.

Abstract: A low alloy steel ingot contains from 0.15 to 0.30% of C, from 0.03 to 0.2% of Si, from 0.5 to 2.0% of Mn, from 0.1 to 1.3% of Ni, from 1.5 to 3.5% of Cr, from 0.1 to 1.0% of Mo, and more than 0.15 to 0.35% of V, and optionally Ni, with a balance being Fe and unavoidable impurities. Performing quality heat treatment including a quenching step and a tempering step to the low alloy steel ingot to obtain a material, which has a grain size number of from 3 to 7 and is free from pro-eutectoid ferrite in a metallographic structure thereof, and which has a tensile strength of from 760 to 860 MPa and a fracture appearance transition temperature of not higher than 40° C.

Abstract: The present invention relates to the application of at least partially bainitic or interstitial martensitic heat treatments on steels, often tool steels or steels that can be used for tools. The first tranche of the heat treatment implying austenitization is applied so that the steel presents a low enough hardness to allow for advantageous shape modification, often trough machining. Thus a steel product is obtained which can be shaped with ease and whose hardness can be raised to a higher working hardness with a simple heat treatment at low temperature (below austenitization temperature).

Abstract: High cleanliness spring steel useful in manufacturing a spring with SiO2-based inclusions being extremely controlled and excellent in fatigue properties is provided. High cleanliness spring steel which is steel containing; C: 1.2% (means mass %, hereafter the same with respect to the component) or below (not inclusive of 0%), Si: 1.2-4%, Mn: 0.1-2.0%, Al: 0.01% or below (not inclusive of 0%), and the balance comprising iron with inevitable impurities, wherein; the total of oxide-based inclusions of 4 or above of L (the large diameter of an inclusion)/D (the short diameter of an inclusion) and 25 ?m or above of D and oxide-based inclusions of less than 4 L/D and 25 ?m or above of L, in the oxide-based inclusions of 25 mass % or above of oxygen concentration and 70% (means mass %, hereafter the same with respect to inclusions) or above of SiO2 content when Al2O3 +MgO+CaO+SiO2+MnO=100% is presumed, out of inclusions in the steel, is 20 nos./500 g or below.

Abstract: A forging heat resistant steel of an embodiment contains in percent by mass C: 0.05-0.2, Si: 0.01-0.1, Mn: 0.01-0.15, Ni: 0.05-1, Cr: 8 or more and less than 10, Mo: 0.05-1, V: 0.05-0.3, Co: 1-5, W: 1-2.2, N: 0.01 or more and less than 0.015, Nb: 0.01-0.15, B: 0.003-0.03, and a remainder comprising Fe and unavoidable impurities.

Abstract: Provided is a welding metal in which the chemical component composition thereof is appropriately controlled; an A value that is specified by a predetermined relational expression satisfies the requirement of being 3.8% to 9.0%; an X value that is specified by a predetermined relational expression satisfies the requirement of being 0.5% or greater; the area percentage of carbide particles having a circle-equivalent diameter of 0.20 ?m or greater in the welding metal is 4.0% or less; and the number of carbide particles having a circle-equivalent diameter of 1.0 ?m or greater is 1000 particles/mm2 or less. This welding metal, which can exhibit not only high strength but also good low-temperature toughness and good drop-weight characteristics, is useful as a material for a pressure vessel in a nuclear power plant.

Abstract: A method forms a steel sheet having a tensile strength of 440 MPa or more into a press-formed part including a flange portion and other portions by press forming. The method includes: heating the steel sheet to a temperature of 400° C. to 700° C.; and press-forming the heated steel sheet by crash forming to obtain a press-formed part such that an average temperature difference among a flange portion and other portions of the press-formed part immediately after the formation is kept within 100° C. Geometric changes such as springback that occur in a panel can thus be suppressed, dimensional accuracy of the panel can be enhanced accordingly, and the desired mechanical properties can easily be obtained in the press-formed part.

Abstract: A method of forming a steel sheet having a tensile strength of 440 MPa or more into a press-formed part including a flange portion and other portions by press forming includes: heating the steel sheet to a temperature of 400° C. to 700° C.; and press-forming the heated steel sheet using draw forming to obtain a press-formed part, with the steel sheet being held at a press bottom dead point in the die for one second to five seconds. Geometric changes such as springback that occur in a panel can thus be suppressed, the dimensional accuracy of the panel can be enhanced, and the desired mechanical properties can easily be obtained in the press-formed part.

Abstract: Provided is a welding metal in which a predetermined chemical component composition is satisfied, the A value as specified by formula (1) is 3.8% to 9.0%, and the surface area percentage of carbide having a circle-equivalent diameter of 0.20 ?m or greater in the welding metal is 4.0% or less. A value=0.8×[C]?0.05×[Si]+0.5×[Mn]+0.5×[Cu]+[Ni]?0.5×[Mo]+0.2×[Cr]??(1) (Provided that [C], [Si], [Mn], [Cu], [Ni], [Mo] and [Cr] are the C, Si, Mn, Cu, Ni, Mo and Cr content (by mass percent), respectively) The welding metal is useful as a material for a pressure vessel of a nuclear power plant as the welding metal is high in strength and has good low-temperature toughness and drop-weight characteristics.

Abstract: There is provided a metal powder for powder metallurgy including Zr and Si in a manner such that following conditions of (A) and (B) are satisfied, wherein a remainder thereof includes at least one element selected from the group consisting of Fe, Co and Ni, (A) the mass ratio of a content of Zr to a content of Si is 0.03 to 0.3, and (B) the content of Si is 0.35 to 1.5% by mass.

Abstract: A high strength spring steel suppresses ferrite decarburization in a surface layer of a predetermined wire rod manufactured by hot rolling therefrom and possesses excellent decarburization resistance, as compared to conventional high strength spring steel, by optimizing the amount of C, Si, Mn, Cr, Mo and Sb to be added. The spring steel contains, under a certain relationship: 0.35 mass %?C?0.45 mass %; 1.75 mass %?Si?2.40 mass %; 0.1 mass %?Mn?1.0 mass %; 0.01 mass %?Cr<0.50 mass %; 0.01 mass %?Mo?1.00 mass %; P?0.025 mass %; S?0.025 mass %; and O?0.0015 mass %; and at least one selected from 0.035 mass %?Sb?0.12 mass % and 0.035 mass %?Sn?0.20 mass %.

Abstract: The invention relates to a steel alloy for a low alloy steel for producing high-tensile, weldable, hot-rolled seamless steel tubing, in particular construction tubing. The chemical composition (in % by mass) is: 0.15-0.18% C; 0.20-0.40% Si; 1.40-1.60% Mn; max. 0.05% P; max. 0.01% S; >0.50-0.90% Cr; >0.50-0.80% Mo; >0.10-0.15% V; 0.60-1.00% W; 0.0130-0.0220% N; the remainder is made up of iron with production-related impurities; with the optional addition of one or more elements selected from Al, Ni, Nb, Ti, with the proviso that the relationship V/N has a value of between 4 and 12 and the Ni content of the steel is not more than 0.40%.

Abstract: A weld metal according to the present invention has a specific chemical composition, contains carbide particles each having an equivalent circle diameter of greater than 0.5 ?m in a number of 0.25 or less per micrometer of grain boundary length, and has an A-value as specified by Formula (1) of 0.12 or more, Formula (1) expressed as follows: A-value=([V]/51+[Nb]/93)/([Cr]/52+[Mo]/96) ??(1) where [V], [Nb], [Cr], and [Mo] are contents (percent by mass) of V, Nb, Cr, and Mo, respectively, in the weld metal.

Abstract: Steel for induction hardening wherein coarsening of austenite crystal grains can be prevented even at a high temperature of over 1100° C. such as which occurs at projecting parts of steel parts at the time of induction hardening, the steel for induction hardening characterized by containing, by mass %, C: 0.35 to 0.6%, Si: 0.01 to 1%, Mn: 0.2 to 1.8%, S: 0.001 to 0.15%, Al: 0.001 to 1%, Ti: 0.05 to 0.2%, and Nb: 0.001 to 0.04%, restricting N: 0.0060% or less, P: 0.025% or less, and O: 0.0025% or less, satisfying Nb/Ti?0.015, and having a balance of iron and unavoidable impurities.

Abstract: A cold die steel excellent in the characteristic of suppressing dimensional change, which has a chemical composition in mass %: C: 0.7% or more and less than 1.6%, Si: 0.5 to 3.0%, Mn: 0.1 to 3.0%, P: less than 0.05% including 0%, S: 0.01 to 0.12%, Cr: 7.0 to 13.0%, one or two elements selected from the group consisting of Mo and W: amounts satisfying the formula (Mo+(W/2))=0.5 to 1.7%, V: less than 0.7% including 0, Ni: 0.3 to 1.5%, Cu: 0.1 to 1.0% and Al: 0.1 to 0.7%. Preferably, the die steel satisfies the formula in mass %: Ni/Al=1 to 3.7. It is preferred that the die steel also satisfies the following formula in mass %: (Cr?4.2×C)=5 or less and (Cr?6.3×C)=1.4 or more and that it contains 0.3% or less of Nb.

Abstract: The present invention provides steel plate or steel pipe with small occurrence of the Bauschinger effect and methods of production of the same, particularly steel pipe used for steel pipe for oil wells or line pipe with a small drop in the compression strength in the circumferential direction due to the Bauschinger effect when expanded and methods of production of the same, that is steel plate or steel pipe with small occurrence of the Bauschinger effect characterized by having a dual-phase structure substantially comprising a ferrite structure and fine martensite which is dispersed in the ferrite structure. Further, this steel plate or steel pipe contains, by mass %, C: 0.03 to 0.30%, Si: 0.01 to 0.8%, Mn: 0.3 to 2.5%, P: 0.03% or less, S: 0.01% or less, Al: 0.001 to 0.01%, and N: 0.01% or less and a balance of iron and unavoidable impurities.

Abstract: A case hardened gear steel having enhanced core fracture toughness includes by weight percent about 16.3Co, 7.5Ni, 3.5Cr, 1.75Mo, 0.2W, 0.11C, 0.03Ti, and 0.02V and the balance Fe, characterized as a predominantly lath martensitic microstructure essentially free of topologically close-packed (TCP) phases and carburized to include fine M2C carbides to provide a case hardness of at least about 62 HRC and a core toughness of at least about 50 ksi?in.

Abstract: Provided is a maraging steel strip which has such a composition that can reduce the content of TiN acting as the starting point of fatigue fracture in a high-cycle region, and the bending fatigue strength of which has been improved by the precipitation hardening effect yielded by precipitating coherent nitrides in the nitrided structure. A maraging steel strip produced by nitriding a managing steel which contains by mass, C: 0.01% or less, Si: 0.1% or less, Mn: 0.1% or less, P: 0.01% or less, S: 0.005% or less, Ni: 8.0 to 22.0%, Cr: 0.1 to 8.0%, Mo: 2.0 to 10.0%, Co: 2.0 to 20.0%, Ti: 0.1% or less, Al: 2.5% or less, N: 0.03% or less, and O: 0.005% or less, with the balance being Fe and unavoidable impurities, wherein Baker-Nutting orientation relationship with an orientation difference within 10° exists between the Cr nitride precipitated in the nitrided layer and the matrix martensite.

Abstract: A steel having excellent formability, fatigue endurance after quenching, low temperature toughness, resistance for hydrogen embrittlement, and corrosion fatigue endurance. A method includes heating a steel slab at 1160° C. to 1320° C., hot-finish-rolling the steel slab at a finisher delivery temperature of 750° C. to 980° C., and then coiling the hot-rolled steel at a coiling temperature of 560° C. to 740° C. after slow cooling for a time of 2 seconds or more to produce a hot-rolled steel strip having a structure in which the ferrite grain diameter df corresponding to a circle is 1.1 ?m to less than 1.2 ?m and the ferrite volume fraction Vf is 30% to 98%, the steel slab containing 0.18 to 0.29% of C, 0.06 to 0.45% of Si, 0.91 to 1.85% of Mn, 0.019% or less of P, 0.0029% or less of S, 0.015 to 0.075% of sol. Al, 0.0049% or less of N, 0.0049% or less of O, 0.0001 to 0.0029% of B, 0.001 to 0.019% of Nb, 0.001 to 0.029% of Ti, 0.001 to 0.195% of Cr, and 0.001 to 0.

Abstract: Disclosed is steel for a leaf spring with high fatigue strength containing, in mass percentage, C: 0.40 to 0.54%, Si: 0.40 to 0.90%, Mn: 0.40 to 1.20%, Cr: 0.70 to 1.50%, Ti: 0.070 to 0.150%, B: 0.0005 to 0.0050%, N: 0.0100% or less, and a remainder composed of Fe and impurity elements. Also disclosed is a high fatigue-strength leaf spring part obtained by forming the steel. The steel for a leaf spring is prepared to have a Ti content and a N content to satisfy a relation of Ti/N?10. Preferably, the leaf spring part is subjected to a shot peening treatment in a temperature range of the room temperature through 400° C. with a bending stress of 650 to 1900 MPa being applied to it.

Abstract: An outer ring, an inner ring and a roller serving as a bearing component that adopts as a source material a steel ensuring a large fracture toughness value and also having an alloy element added thereto in a reduced amount and also provides sufficient wear resistance, are configured of a steel containing 0.15-0.3% by mass of carbon, 0.15-0.7% by mass of silicon, and 0.15-1.0% by mass of manganese, with a remainder of iron and an impurity, and have a raceway/rolling contact surface included in a region having a carbon enriched layer and a nitrogen enriched layer. In the nitrogen enriched layer the raceway/rolling contact surface has a nitrogen concentration equal to or larger than 0.3% by mass.

Abstract: A high strength mild steel alloy is provided. In addition, a process for making the high strength steel alloy is also provided. The process includes providing a mild steel alloy with a chemical composition in weight percent within a range of 0.12-0.25 carbon, 0.30-1.70 manganese, 0.50 max silicon, 0.10 max chromium, 0.01 max niobium, 0.035 max titanium, 0.01 vanadium, 0.10 max molybdenum, 0.10 max nickel, 0.015 max sulfur, 0.025 max phosphorus, 0.012 max nitrogen, 0.003 max boron, and 0.015-0.065 aluminum. Hot rolled steel strip with a thickness of less than 10 millimeters is cold rolled to produce a cold rolled steel sheet that has a thickness that is less than 50% of the hot rolled steel strip thickness which is subsequently recovery annealed to provide sheet material having a yield strength greater than 550 megapascals (MPa) and a percent elongation to failure greater than 3.5%.

Abstract: The weld metal of the present invention is formed by gas shield arc welding using a flux-cored wire, has a predetermined chemical component composition, and contains 20% or more of Ti. The amount of Ti-containing oxide particles having a circle-equivalent diameter of 0.15-1.0 ?m is at least 5000 per square mm, the amount of V per total mass of weld metal present as a compound within the weld metal is 0.002% or more, and the average circle equivalent diameter of V-containing carbide present in the weld metal is 15 nm or less.

Abstract: A hot work tool steel family with exceptional thermal diffusivity, toughness (both fracture toughness and notch sensitivity resilience CVN—charpy V-notch) and trough hardenability has been developed. Mechanical resistance and yield strength at room and high temperatures (above 600° C.) are also high, because the tool steels of the present invention present a high alloying level despite the high thermal conductivity. Given the exceptional resistance to thermal fatigue and thermal shock, wear resistance can be severely increased for many applications requiring simultaneously resistance to thermal cracking and wear like is the case for some forging and some parts of die casting dies.

Abstract: A low-chromium hot-work tool steel consisting of (in wt-%): C 0.08-0.40, N 0.015-0.30, C+N 0.30-0.50, Cr 1-4, Mo 1.5-3, V 0.8-1.3, Mn 0.5-2, Si 0.1-0.5, optionally Ni<3, Co?5, B<0.01, Fe balance apart from impurities, and a process for making a low-chromium hot-work tool steel article having increased tempering resistance.

Abstract: A steel for nitriding having a chemical composition consisting of, by mass percent, C: 0.07-0.14%, Si: 0.10-0.30%, Mn: 0.4-1.0%, S: 0.005-0.030%, Cr: 1.0-1.5%, Mo: ?0.05% (including 0%), Al: 0.010% or more to less than 0.10%, V: 0.10-0.25%, optionally at least one element selected from Cu: ?0.30% and Ni: ?0.25% [0.61Mn+1.11Cr+0.35Mo+0.47?2.30], and the balance of Fe and impurities. P, N, Ti and O among the impurities are P: ?0.030%, N: ?0.008%, Ti: ?0.005%, and O: ?0.0030%. The steel is easily subjected to cutting before nitriding and suitable for use as an automobile ring gear. The nitrided component having a surface hardness of 650-900 HV, core hardness being ?150 HV, and effective case depth of ?0.15 mm has excellent bending fatigue strength and surface fatigue strength although the content of Mo is as low as ?0.05% and has a small amount of expansion caused by nitriding.

Abstract: A tool steel family with outstanding thermal diffusivity, hardness and wear resistance has been developed, also exhibiting good hardenability. Also its mechanical strength, as well as its yield strength, at ambient and high temperature (superior to 600° C.) are high, due to a high alloying level in spite of the high thermal conductivity. Because of its high thermal conductivity and good toughness, steels of this invention have also good resistance to thermal fatigue and thermal shock. This steels are ideal for discontinuous processes where it is interesting to reduce cycle time and that require high hardness and/or wear resistance (plastic injection molding, other plastic forming processes and curing of thermosets, hot forming of sheet . . . ). These tool steels are also appropriate for processes requiring high wear resistance and good resistance to thermal fatigue (forging, hot stamping, light-alloy injection . . . ).

Abstract: Steel for a high temperature joining process suitable, in particular for components intended for applications with high demands on fatigue and toughness properties, such as bearing components, comprising the following composition in weight-%: 0.5-0.8 C, 0- 0.15 Si, 0-1.0 Mn, 0.01-2.0 Cr, 0.01-1.0 Mo, 0.01-2.0 Ni, 0.01-1.0 of V or 0.01-1.0 of Nb, or 0.01-1.0 of both V and Nb, 0-0.002 S, 0-0.010 P, 0-0.15 Cu, 0.010-1.0 Al, the remainder being Fe and normally occurring impurities.

Abstract: A forged steel for components for nuclear power plants meets a specific chemical composition. The grain size number of a metal structure thereof is 4.5 to 7.0 in terms of ASTM grain size number. It is preferred that the content of N is 0.0100 mass % or more when the mass ratio (Al/N) of the content of Al to the content of N is 1.93 or more, and that the content of Al is 0.022 mass % or more when the mass ratio (Al/N) of the content of Al to the content of N is less than 1.93. The forged steel for components for nuclear power plants exhibits excellent strength, toughness and hydrogen cracking resistance even after being subjected to a stress relief heat treatment subsequent to welding.

Abstract: A NiCrMoV alloy and a turbine component are disclosed. The NiCrMoV alloy includes at least about 0.06%, at least about 3.40% nickel, between about 0.22% and about 0.30% carbon, up to about 0.60% molybdenum, up to about 0.15% vanadium, up to about 2.00% chromium, up to about 0.012% phosphorus, up to about 0.007% sulfur, up to about 0.10% silicon, up to about 0.002% antimony, up to about 0.008% arsenic, up to about 0.012% tin, and up to about 0.015% aluminum and/or is resistant to embrittlement at temperatures above 700° F.

Abstract: Disclosed is a carburized machine part which is free from the problem of decreased strength at edge-shaped parts due to excess introduction of carbon. The machine part is produced by processing a case hardening steel of the alloy composition consisting essentially of, by weight %, C: 0.1-0.3%, Si: 0.5-3.0%, Mn: 0.3-3.0%, P: up to 0.03%, S: up to 0.03%, Cu: 0.01-1.00%, Ni: 0.01-3.00%, Cr: 0.3-1.0%, Al: up to 0.2% and N: up to 0.05% and the balance of Fe and inevitable impurities, and satisfying the following condition: [Si %]+[Ni %]+Cu %]?[Cr %]>0.5 and carburizing by vacuum carburization.

Abstract: To provide weld metal that has a high strength and toughness in the as-welded condition or in the annealed condition. The weld metal of the present invention contains by weight %, C: 0.04-0.15%, Si: 0.50% or less, Mn: 1.0-1.9%, Ni: 1.0-4.0%, Cr: 0.10-1.0%, Mo: 0.20 to 1.2%, Ti: 0.010-0.060%, Al: 0.030% or less, O: 0.15-0.060%, N: 0.010% or less, Fe and inevitable impurities as the remaining contents. The weld metal is further characterized by the fact that the ratio of Ti content (%) to Si content (%) i.e., [compound type Ti]/[compound type Si] is more than 1.5, and the number A defined by the following formula is 0.50 or more, wherein A=[Ti]/([O]?1.1×[Al]+0.05×[Si]).

Abstract: Steel is described having a chemical composition, in weight-%, of 0.3 to 0.5% carbon (C), from traces to a max. of 1.5% silicon (Si), 0.2 to 1.5% manganese (Mn), 0.01 to 0.2% sulfur (S), 1.5 to 4% chromium (Cr), 1.5 to 5% nickel (Ni), 0.5 to 2% molybdenum (Mo), which at least partially may be replaced by twice as much tungsten (W), 0.2 to 1.5% vanadium (V), from traces to a max. of 0.2% rare earth metals, and a balance essentially of only iron, impurities and accessory elements in normal amounts. In addition, a method for manufacturing a blank of the steel and a process for manufacturing a cutting tool body or holder for cutting tools of the steel is described.

Abstract: The invention relates to a manufacturing process for steel blanks. The invention relates in particular to a manufacturing process of a steel blank comprising electroslag remelting (ESR—ElectroSlag Remelting) or vacuum arc remelting (VAR—Vacuum Arc Remelting) to obtain very good mechanical properties. The blanks obtained can be used especially in the field of the manufacture of pressurized equipment elements and especially cannon tubes.

Abstract: A rolled steel bar or a wire rod for hot forging capable of coping with both bending/surface fatigue strength of components and machinability at a high level includes: a composition containing, in mass %, C: 0.1 to 0.25%, Si: 0.01 to 0.10%, Mn: 0.4 to 1.0%, S: 0.003 to 0.05%, Cr: 1.60 to 2.00%, Mo: 0.10% or less (including 0%), Al: 0.025 to 0.05%, and N: 0.010 to 0.025%, where a value of fn1 represented in a following formula (1) satisfies 1.82?fn1?2.10: fn1=Cr+2×Mo (1); impurities containing P: 0.025% or less, Ti: 0.003% or less, and O (oxygen): 0.002% or less; and a cross section in which a maximum value/a minimum value of an average ferrite grain diameter is 2.0 or less when measurement by observation is randomly carried out in 15 visual fields with an area per visual field set to be 62500 ?m2.

Abstract: A steel for electron-beam welding according to the present invention includes at least C: 0.02% to 0.10%, Si: 0.03% to 0.30%, Mn: 1.5% to 2.5%, Ti: 0.005% to 0.015%, N: 0.0020% to 0.0060%, and O: 0.0010% to 0.0035%, further includes S: limited to 0.010% or less, P: limited to 0.015% or less, and Al: limited to 0.004% or less, with a balance including iron and inevitable impurities. An index value CeEBB obtained by substituting composition of the steel into following Formula 1 falls in the range of 0.42 to 0.65%, the number of oxide having an equivalent circle diameter of 1.0 ?m or more is 20 pieces/mm2 or less at a thickness center portion in cross section along the thickness direction of the steel, and the number of oxide containing Ti of 10% or more and having an equivalent circle diameter of not less than 0.05 ?m or more and less than 0.5 ?m falls in the range of 1×103 to 1×105 pieces/mm2 at the thickness center portion.

Abstract: Provided is a bearing steel capable of exhibiting excellent cold workability in cold working that follows spheroidizing annealing and also capable of ensuring excellent abrasion resistance and rolling fatigue characteristics as a bearing member or the like. The bearing steel contains C: 0.9 to 1.10%, Si: 0.05 to 0.49%, Mn: 0.1 to 1.0%, P: not more than 0.05% (excluding 0%), S: not more than 0.05% (excluding 0%), Cr: 0.03 to 0.40%, Al: not more than 0.05% (excluding 0%), N: 0.002 to 0.025%, Ti: not more than 0.0030% (excluding 0%), and 0: not more than 0.0025% (excluding 0%), with the remainder being iron and unavoidable impurities. The average aspect ratio of cementite is not more than 2.00, the average circle-equivalent diameter of cementite is 0.35 to 0.6 ?m, and the number density of cementite having a circle-equivalent diameter of not less than 0.13 ?m is not less than 0.45/?m2.

Abstract: An outer ring, an inner ring and a ball serving as mechanical components configuring a deep groove ball bearing are formed of steel containing at least 0.11 mass % and not more than 0.15 mass % of carbon, at least 0.1 mass % and not more than 0.25 mass % of silicon, at least 0.15 mass % and not more than 0.35 mass % of manganese, at least 3.2 mass % and not more than 3.6 mass % of nickel, at least 4 mass % and not more than 4.25 mass % of chromium, at least 4 mass % and not more than 4.5 mass % of molybdenum and at least 1.13 mass % and not more than 1.33 mass % of vanadium with a remainder consisting of iron and impurity, and have raceway/rolling contact surfaces, the surface being included in a region having a nitrogen enriched layer having a nitrogen concentration of at least 0.05 mass %, the nitrogen enriched layer having a carbon concentration and the nitrogen concentration, in total, of at least 0.55 mass % and not more than 1.9 mass % at a depth of 0.1 mm from the surface.

Abstract: In light of the recent analytical technology demanded of fast and accurate measurement of high purity materials, a zirconium crucible is provided for melting an analytical sample and is capable of inhibiting the inclusion of impurities from the crucible by using a high-purity crucible, improving the durability of high-purity zirconium as an expensive crucible material, and increasing the number of times that the zirconium crucible can be used. With this zirconium crucible used for melting an analytical sample in the pretreatment of the analytical sample, the purity excluding gas components is 3N or higher, and the content of carbon as a gas component is 100 mass ppm or less.

Abstract: Provided are: a steel wire rod material for a high-strength spring, which does not undergo the increase in deformation resistance arising from the increase in hardness and can exhibit good wire-drawing processability and the like even when a heat treatment, which deteriorates productivity, is eliminated or a simplified and rapid heat treatment is employed instead; a useful method for producing the steel wire rod material for a high-strength spring; a high-strength spring produced using the steel wire rod material for a high-strength spring as a material; and others. This steel wire rod material for a high-strength spring is a steel wire rod material that has been hot-rolled already, and has a texture having a specified chemical composition and mainly composed of pearlite, wherein the average value (Pave) of the pearlite nodule size numbers and the standard deviation (P?) of the pearlite nodule size numbers fulfill the following formulae (1) and (2), respectively: 9.5?Pave?12.0;??(1) and 0.2?P??0.

Abstract: A high hardness, high strength, and high impact toughness steel for military articles such as armor plates, bodies of deep penetrating bombs, and missiles. The steel has a HRC of 54 to 56, UTS of 290 to 305 ksi, YS of 225 to 235 ksi, an elongation of 13-14%, a reduction of area of 47-50% and a Charpy V-notch impact toughness energy of 26 to 28 ft-lbs at room temperature. The microstructure of the steel consists essentially of fine packets of martensitic lathes, fine titanium carbides as centers of growth of the martensitic lathes, and retained austenite.

Abstract: A high-strength steel sheet according to the present invention not only is suitably adjusted in its chemical elements composition, but also has a DE value defined by the following Equation (1) of 0.0340% or more, and a carbon equivalent Ceq defined by the following Equation (2) of 0.45% or less: DE value=[Ti]+[Nb]+0.3[V]+0.0075[Cr]??(1) where, [Ti], [Nb], [V], and [Cr] represent contents (mass %) of Ti, Nb, V, and Cr, respectively; Ceq=[C]+[Mn]/6+([Cr]+[Mo]+[V])/5+([Cu]+[Ni])/15 ??(2) where, [C], [Mn], [Cr], [Mo], [V], [Cu], and [Ni] represent contents (mass %) of C, Mn, Cr, Mo, V, Cu, and Ni, respectively. A high-strength steel sheet resistant to strength reduction and good in low-temperature toughness of HAZ even when subjected for a long time to a stress-relief annealing process after being processed by welding, is provided.

Abstract: Disclosed is a high-strength steel plate having a predetermined chemical composition, in which a microstructure of the steel plate at a depth of one-fourth to one half the thickness from a surface has an area fraction of bainite of 90% or more, an average lath width of bainite of 3.5 ?m or less, and a maximum equivalent circle diameter of martensite-austenite constituents in bainite of 3.0 ?m or less. The steel plate exhibits high strengths and good drop weight properties and is useful as structural materials for offshore structure, ships, and bridges, as well as materials for pressure vessels in nuclear power plants.